Method for producing a food body with surface color indicia

ABSTRACT

An article comprising a substrate such as cellulose casing having thereon a desired indicia such as grill marks or a corporate logo, which in turn comprises a water soluble underlayer such as caramel and a water insoluble binder-sealant layer such as shellac. Also included are an indicia-containing processable food package, a method for preparing the substrate-indicia article, a method for making an indicia-containing food product, and an edible food product as for example a frankfurter having a desired indicia on its outer surface.

RELATED APPLICATION

This application is a division of prior U.S. application Ser. No.326,560, filed Mar. 24, 1989, now U.S. Pat. No. 4,985,260, which is acontinuation-in-part of application Ser. No. 191,100, filed May 6, 1988.

TECHNICAL FIELD

This invention relates to an article having thereon a desired indicia oforganic coloring matter as for example a cellulosic food casing with theorganic color indicia on its surface, a processable food packagecomprising an indicia-containing casing filled with processable food towhich the color indicia is transferred during processing, an edible foodproduct with the color indicia on its outer surface as for exampleprocessed frankfurter with grill marks, and a method for making theindicia-containing processed food product.

BACKGROUND OF THE INVENTION

As used herein, "indicia" means a distinctive predetermined patternwhich the manufacturer of an edible product wishes to have applied onthe outer surface of a food product. Indicia includes "logo" which is anintelligible Pattern as for example one or more letters, pictures orsymbols. Indicia also includes marks which have a pleasing connotationto the consumer, as for example grill marks.

There is a long-standing need for an edible food product with a desiredindicia on its outer surface. For example, food processors would like tohave their edible product identified by their company logo to indicatehigh and consistent quality. Also, other types of indicia such as grillmarks on frankfurters are desirable for esthetic reasons.

Frankfurters are prepared by processing of moist emulsion at elevatedtemperature and in a moist environment inside casing, usuallymanufactured from cellulose, i.e. cellulosic casings. The latter aretypically supplied to the food processor in the form of shirred sticks,i.e. highly compressed pleats which may be on the order of 1/150 oftheir as-manufactured flat length. The shirred stick with one closed endis attached to a stuffing machine which deshirrs and deplugs the closedend of the stick whereupon emulsion is pumped into and fills the casing.The emulsion-filled casing is formed into short links and at high speed,e.g. 250 fpm as it is removed from the stuffing machine. The emulsion iscooked within the casing during the processing step to form afrankfurter. After processing, the cellulosic casing is peeled from thefrankfurter outer surface using high speed equipment, e.g. 500 fpm, andthe casing is discarded.

For high speed production, the moisture content of the cellulosic casingmust be closely maintained during both the shirring and the stuffingsteps. This is necessary so that the casing has the necessaryflexibility for moving without breakage yet adequate physical integrityfor mechanical handling during deshirring and stuffing. Plasticizerssuch as glycerine are also included in the casing to partially satisfythese requirements.

Those skilled in the food processing art recognize that it is notcommercially practical to impart color indicia on frankfurters afterprocessing and casing removal. The prior art has proposed this be donefor example by searing the frankfurter to form grill marks, as taught inU.S. Pat. No. 4,384,006. One problem with this approach is the need foradditional and complex high speed machinery to match the frankfurterproduction rate. Another problem is that searing requires penetration ofthe thin outer skin of the frankfurter, thereby creating a sanitationissue.

Another approach to providing an edible food body outer surface withcolor indicia is to form the indicia on the cellulosic substrate andthen transfer the indicia to the food body outer surface duringprocessing. There are a number of problems to this approach which havenot been collectively overcome. The indicia must be formed of materialwhich has been approved by governmental authorities for direct contactwith food, and this requirement severely restricts the selection ofconstituents. Further, the indicia as applied to the substrate shouldhave at least some degree of abrasion resistance. If for example theindicia-containing substrate is food casing to be shirred, the indiciamust retain its integrity during extreme distortions of the substratewhich are characteristic of the pleat-forming and compression steps ofshirring, as well as pleat elimination and straightening out of thecasing during the succeeding inflation and stuffing. Even if the casingis not shirred but instead rolled and fed to the stuffing machine asroll stock, there is considerable distortion by virtue of the bendingand compression of the casing to form roll stock.

A further requirement is that the indicia must not cause transfer("ink-offsetting") or even "blocking" during handling or storage ofindicia-containing substrate, i.e. transfer or even adhesion to eitherthe substrate or another indicia when different substrate portions arepressed together as for example in shirring, rolling or stacking.

Another requirement of any food casing color indicia system is that theindicia must have at least some degree of moisture insensitivity. Thatis, the color indicia is preferably insoluble in water at ambienttemperature because the casing itself must contain substantial moisturein the as-manufactured condition, as previously explained. If shirringis to be employed, the casing is further moisturized during shirring. Acolor indicia which is even partially soluble in water would smear andcould not transfer as a clearly defined sharp indicia.

Still another requirement of a food casing color indicia system is thatthe indicia must substantially completely transfer to the contiguousedible surface with sharp definition. Less than complete transfer wouldresult in an indicia which has poor definition, unevenness or be toofaint when compared with the surrounding surface. This occurs when oneattempts to pass color indicia through the casing wall in the presenceof moisture (from the outer surface to the inner surface) to the sausageduring stuffing, as described in U.S. Pat. No. 2,301,564.

Color indicia may possibly be formed from dyes or pigments, but thereare serious limitations with each approach. Water soluble dyes areextremely moisture sensitive, i.e. they tend to run away from theas-applied indicia leaving at best a fainter mark with poor definition.Solvent soluble dyes are not moisture sensitive but are not approved bygovernmental authorities for human consumption. On the other hand,organic pigments are unavailable in certain colors as for example brown,and in general are not approved by governmental authorities for humanconsumption.

An object of this invention is to provide an article comprising asubstrate with a desired color indicia thereon which is approved fordirect contact with food, moisture insensitive, and which issubstantially completely transferable from the substrate to a contiguousedible surface.

Another object is to provide a processable food package comprising acasing filled with processable food in direct contact with the casinginner surface, the latter having thereon a desired color indicia whichis substantially completely transferable from the the casing innersurface to the food outer surface during in-situ processing of the food.

A further object is to provide an edible food product having on itsouter surface a desired color indicia.

A still further object is to provide a method for making processed foodproduct in which a casing with a desired color indicia on its innersurface is stuffed with a processable food mass, the color indicia issubstantially completely transferred to the food mass outer surfaceduring food processing and the casing is thereafter removed from theprocessed food mass without loss of the color indicia on the food massouter surface.

Other objects and advantages of this situation will be apparent from theensuing disclosure and appended claims.

SUMMARY OF INVENTION

One aspect of this invention is an article comprising a substrate (forexample plasticized cellulose or thermoplastic film) having thereon adesired indicia comprising a water soluble dry colorant under layer innondiffusible association with said substrate and a binder-sealant layersuperimposed over and entirely enclosing the colorant layer top surfacein adhering relationship, the binder-sealant perimeter outwardlyextending beyond the colorant layer extremities so as to directlycontact the surrounding substrate in adhering relationship therewith,said binder-sealant having a melting point above about 100° F. and beingwater insoluble. The binder-sealant covered colorant indicia issubstantially completely transferable from the substrate to a contiguousedible surface in the presence of moisture.

In this article, the bottom surface of the colorant layer may be incontiguous association with the substrate. Alternatively, a firstbinder-sealant layer may have its bottom surface adhered to thesubstrate with the under surface of the colorant layer superimposed onthe top surface of the first binder-sealant in adhering andnondiffusible relationship therewith. A second binder-sealant layercomprises the aforementioned binder-sealant superimposed over thecolorant layer. The outer perimeter of at least one of the first andsecond binder-sealant layers outwardly extends beyond the colorant layerextremities for direct contact with the surrounding substrate. The firstbinder-sealant also has a melting point above about 100° F. and is waterinsoluble. The first binder-sealant and the second binder-sealant may beformed of identical or different materials.

Another aspect of this invention is a processable food packagecomprising a casing or tube filled with water moisture-containingprocessable food having its outer surface in direct contact with thecasing inner surface. The latter is a substrate for the aforedescribedindicia, and the binder-sealant top surface is in contiguous associationwith the food outer surface. Preferably the casing is either cellulosicor formed from thermoplastic film. The indicia is substantiallycompletely transferable from the casing inner surface to the watermoisturized food outer surface during processing thereof in the casing.The bottom surface of the colorant layer may be in contiguousassociation with the substrate. Alternatively, a first binder-sealantlayer may have its bottom surface adhered to the substrate, and theunder surface of the colorant layer is superimposed on the top surfaceof the first binder-sealant layer in adhering and nondiffusiblerelationship therewith. In this sandwich embodiment of the article, asecond binder-sealant layer comprises the aforementioned binder-sealantsuperimposed over the colorant layer. The first binder-sealant also hasa melting point above about 100° F. and is water insoluble.

Still another aspect of this invention is a method for preparing anindicia-containing substrate flexible article. A plasticized substrateis provided, and a portion of a desired indicia is applied theretocomprising a water soluble colorant layer with its bottom surface incontiguous and nondiffusible association with the substrate. At leastthe applied colorant indicia portion is dried, and a mixture comprisinga binder sealant and organic solvent mixture coating is applied asanother indicia portion over the dry colorant layer top surface toentirely enclose same. The coating perimeter extends outwardly beyondthe colorant layer extremities so as to directly contact the substrate.The binder-sealant has a melting point above about 100° F. and is waterinsoluble. The organic solvent is evaporated from the coating so as toform a dry binder-sealant coating entirely enclosing the dry colorantlayer top surface and being adhered thereto and the surroundingsubstrate.

A further inventive method for preparing an indicia-containing substrateflexible article includes the step of applying as a portion of a desiredindicia to the substrate, a water insoluble first binder-sealant andorganic solvent mixture as a coating. The organic solvent is evaporatedfrom the coating to form a dry layer with its bottom surface adhered tothe substrate. Another portion of the indicia is applied from an aqueoussolution, comprising a water soluble colorant layer with its undersurface superimposed on the top surface of the dry first binder-sealantlayer. The so-applied colorant layer is dried so as to be in adheringand nondiffusible relationship with the first binder-sealant. Next awater insoluble second binder-sealant and organic solvent mixturecoating is applied as still another portion of the indicia. This coatingis applied over the colorant layer top surface and extends beyond thecolorant layer extremities so as to entirely enclose same. At least oneof the first and second sealant-binder perimeters extends outwardlybeyond the colorant layer extremities so as to directly contact thesubstrate surrounding surface. The organic solvent is then evaporatedfrom the last-mentioned coating to form a second binder-sealant drycoating entirely enclosing the dry colorant layer top surface, beingadhered thereto and the surrounding substrate. The first binder-sealant,colorant, second binder-sealant sandwich indicia is substantiallycompletely transferable from the substrate to a contiguous ediblesurface in the presence of moisture.

A still further aspect of the invention is a method for making anindicia-containing processed food product as for example frankfurterhaving spaced grill-like marks on its surface. In this method a casingarticle is provided having an plasticized flexible inner surface with awater soluble dry colorant layer having its bottom surface innondiffusible association with the casing and a water insolublebinder-sealant superimposed over and entirely enclosing the colorant topsurface in adhering relationship as a desired indicia. Thebinder-sealant perimeter extends outwardly beyond the colorant layerextremities so as to directly contact the surrounding casing innersurface in adhering relationship. In this method, the casing is filledwith water moisturized processable food such that the water moisturizedfood outer surface is in direct contact with the binder-sealant on thecasing inner surface. The food-containing casing is processed atelevated temperature to cook the food and simultaneously substantiallycompletely transfer the binder-sealant covered colorant indicia from thecasing inner surface to the water moisturized processed food outersurface. The casing article is then peeled from the indicia- containingprocessed food outer surface In a preferred embodiment of this methodthe indicia is bonded to the casing outer surface and the casing articleis thereafter inverted to position the indicia on the casing innersurface prior to filling same with food.

An additional aspect of the invention is an edible food productcomprising a processed food body having on its outer surface a desiredindicia of a water insoluble binder-sealant layer and a water solublecolorant layer. The inner surface of the binder-sealant layer is bondedto the food body outer surface and the colorant is adhered to the outersurface of the binder-sealant. The latter has a melting point aboveabout 100° F.

The invention also contemplates an edible food product comprising aprocessed food body having on its outer surface a desired indiciasandwich. The latter includes a water insoluble first binder-sealantlayer, a water soluble colorant layer and a water insoluble secondbinder-sealant layer. The top surface of the latter is adhered to thefood body outer surface, the upper surface of the colorant layer isadhered to the second binder-sealant layer bottom surface, and the topsurface of the first binder-sealant layer is adhered to the colorantlayer under surface.

In the drawings:

FIG. 1A is a schematic representation of a flexographic system suitablefor bonding indicia on the outer surface of a substrate as for exampleflattened cellulosic casing.

FIG. 1B is a schematic enlarged cross-sectional elevation view of anembodiment of the inventive article comprising a cellulose substrate anddry colorant under layer-binder sealant cover layer indicia.

FIG. 1C is a schematic enlarged cross sectional elevation view of anedible food product to which the FIG. 1B indicia has been transferred,comprising a processed food body having on its outer surface an indiciacomprising a binder-sealant under layer and colorant top layer.

FIG. 1D is a schematic enlarged cross-sectional elevation view ofanother embodiment of the invention article comprising a cellulosesubstrate and an indicia sandwich of a first binder-sealant layer, drycolorant layer and second binder-sealant layer.

FIG. 1E is a schematic enlarged cross-sectional elevation view of anedible food product to which the FIG. 1D indicia has been transferred,comprising a processed food body having on its outer surface an indiciasandwich comprising a second binder-sealant layer, a dry colorant layerand a first binder-sealant top layer.

FIG. 2 is an inflated cellulose food casing substrate having spacedindicia on its outer surface in the form of grill marks.

FIG. 3 is a schematic representation of a system for shirring theindicia-containing cellulose casing article of FIG. 2 with the indiciaon the casing outside surface.

FIG. 4 is a schematic representation of a system for first looselyshirring the FIG. 2 article, inverting and then reshirring the articlewith the indicia on the casing inside surface.

FIG. 5 is a frankfurter with spaced indicia on its outer surface, whichcan be prepared using the FIG. 2 indicia-containing casing article usingthe shirring systems of FIG. 3 or 4.

FIG. 6 is a flattened casing substrate with a mirror image corporatelogo as the indicia on its outer surface, and

FIG. 7 is a frankfurter with the FIG. 6 logo on its outer surface.

DETAILED DESCRIPTION

The preferred substrate of this invention is cellulosic food casingprepared by the well known viscose-xanthation process. In the latter,high quality relatively pure cellulose pulp (either cotton or wood) isfirst converted to alkali cellulose by steeping in a sodium hydroxidesolution, dried and shredded. After a preferred aging step,xanthation--the conversion of alkali cellulose to xanthate cellulose--isaccomplished by reaction with carbon disulfide. The purpose ofxanthation is to enable dispersion of the cellulose in a dilute solutionof sodium hydroxide. This is the viscose formation step in which sodiumhydroxide is absorbed onto the xanthate cellulose which becomes highlyswollen and dissolves over a finite time period. Viscose is essentiallya solution of cellulose xanthate in a solution by sodium hydroxide whichhas been aged to a specific degree of precipitability.

To form a casing the viscose is extruded into a tubular cellulose film,which is converted to cellulose in the extrusion bath by action ofacid-salt, for example sulphuric acid and sodium sulphate. The resultingcellulose casing is preferably passed through several dilute acid bathsto insure completion of the regeneration and to further remove water.

The casing may also be reinforced, as for example by paper, commonlyreferred to as "fibrous" casing. This may be accomplished by coating theviscose on one or both sides of a paper sheet prior to extrusion.

The cellulose casing substrate embodiment of the present invention mayalso contain other ingredients which are conventionally used, e.g.glycerine and/or propylene glycol as humectants or softening agents.Agents for improving the peelability of the casings from food productsmay be optionally coated on the food contacting surface, as for examplecarboxymethyl cellulose and other water soluble cellulose ethers asdescribed in U.S. Pat. No. 3,898,348. Other suitable peeling aidsinclude "Aquapel", a Hercules, Inc. trademarked product comprising alkylketene dimers, the use of which is described in U.S. Pat. No. 3,905,397,and "Quilon", a DuPont Company trademarked product comprising fatty acidchromyl chlorides the use of which is described in U.S. Pat. No.2,901,358.

Liquid smoke may be added to the casing substrate embodiment for colorand flavor transfer to the food product during processing. Thistreatment may be with "as-is" tar-containing liquid smoke as for exampledescribed in U.S. Pat. No. 4,377,187 or with tar-depleted liquid smokeas for example described in U.S. Pat. No. 4,492,918. In this embodimentthe indicia may be applied to the casing substrate either before orafter the liquid smoke treatment.

For practicing this invention in connection with food casings as theindicia substrate, the invention of copending U.S. patent applicationSer. No. 07/191100 filed May 6, 1988 in the names of J. A. Oxley and M.D. Nicholson is preferably employed. In this respect, one surface of thecasing is provided with an indicia and during stuffing, the casingsurface carrying the indicia is brought into direct contact with theedible product stuffed into the casing. The indicia releases from thecasing surface and transfers to the surface of the food product so thatafter stuffing and processing a mirror image of the indicia remains onthe surface of the edible product when the casing is removed. In thoseinstances where the indicia is not identical in the reversed form, theindicia applied to the casing substrate should be in mirror image to theindicia desired on the surface of the edible product.

Casing processing and shirring operations performed after application ofthe indicia material to the casing should not smear or distort theindicia. Otherwise, the indicia, when transferred to the processededible product, is blurred and/or distorted. Application of the indiciamaterial is most easily accomplished by passing the casing through anapplicator which prints or otherwise applies a mirror image of thedesired indicia or pattern onto the surface of the casing.

Preferably the indicia is applied to the outer surface of the casing.Thereafter, the casing is turned inside out so the indicia is on theinside or edible contacting surface. Inverting the casing can beaccomplished prior to stuffing or during stuffing. U.S. Pat. No.4,162,557 discloses a method for inverting casing prior to stuffingwhereas U.S. Pat. No. 4,162,693 discloses a method for inverting casingduring stuffing. Both of these patents are incorporated herein byreference.

The casing can be shirred in a conventional manner with the indicia onthe exterior surface of the casing. If this is done, the casing may beinverted during stuffing to place the indicia on the inside of thecasing and intimate contact with the food products stuffed into thecasing.

As an alternative, the casing with the indicia on its exterior surfacecan be inverted and then shirred. This places the indicia material on aninside surface of the casing so there is no need to invert the casingduring stuffing.

It is conventional during the course of shirring a cellulosic casing tospray the interior surface of the casing with an aqueous solution. Forexample, U.S. Pat. No. 3,981,046 describes a conventional humidificationtechnique in which an aqueous solution is applied as an internal sprayto humidify the casing to raise the moisture content of the casing to alevel better suited for shirring and subsequent stuffing.

Application of the indicia material onto the exterior surface of thecasing is preferably accomplished "off-line" after the casingmanufacturing process is complete, or alternatively "in-line" as part ofthe casing manufacturing process.

Referring now to the FIG. 1A schematic flexographic printing system, theindicia substrate as for example tubular cellulose food casing isunwound from reel 10. This casing which is unwound in flattened form 11,typically has an as-manufactured moisture content of about 15 wt.% water(bone dry basis). This flat casing is directed by at least one guideroll to a further moisturizing system which for example may comprisespray members 12a and 12b positioned for discharging water spray 13 onboth flat surfaces of the semi-finished casing substrate. The purpose ofthis further moisturization to about 19 wt% water (bone dry basis) is tocompensate for the water lost in the indicia dryer downstream from theindicia application section (discussed hereinafter).

The further moisturized flat casing 14 is directed to the colorantapplication system (sometimes referred to in the art as a printing head)including colorant-aqueous solution supply pan 15a and fountain roll 16apositioned for partial immersion in the colorant-aqueous solution poolduring rotation. Fountain roll 16a is provided with a flexible outersurface capable of receiving the colorant-aqueous solution and holdingsame by surface tension. The colorant-aqueous solution containingfountain roll 16a contacts anilox roll 17a having an etched outersurface with many cells to hold the transferred mixture. Anilox roll 17ain turn contacts a printing plate mounted on cylinder 18a. The lattermay for example comprise a rubber strip containing the desired indiciaor pattern. The colorant-aqueous solution is transferred from aniloxroll 17a to the printing plate of cylinder 18a.

The further moisturized flat cellulose casing 14 is directed by backuproll 19a into contact with the colorant solution indiciaportion-dispensing circular printing plate on the outer surface ofcylinder 18a. The desired indicia colorant portion is thereby depositedas a layer on the cellulose casing outer surface as a supportingsubstrate in adhering relation thereto, forming the colorant indiciaportion-containing further moisturized flat cellulose casing 20. Thelatter is directed to first drier 60 for heating by means 62, e.g.electrical or fluid, to evaporate the water from the colorant layer.

The so-dried colorant indicia portion-containing casing 64 is directedto the binder-sealant application system including binder-sealant andorganic solvent mixture supply pan 15b. This system functions in thesame manner as the aforedescribed colorant application system, andincludes supply pan 15b, fountain roll 16b, anilox roll 17b, cylinder18b and backup roll 19b. The binder-sealant and organic solvent mixturelayer is applied over the dried colorant indicia portion in registrytherewith so as to entirely enclose the colorant layer top portion.However, the binder-sealant and organic solvent layer surface area isslightly larger than the colorant surface area with the former'sperimeter outwardly extending beyond the colorant layer extremities soas to directly contact the cellulose substrate.

The flat cellulose casing 66 having the colorant under layer andbinder-sealant and organic solvent over layer indicia is now passed tosecond drier 68 for heating by means 70, e.g. electrical or fluid toevaporate the organic solvent from the over layer so as to form a drybinder-sealant coating entirely enclosing the dry colorant layer topsurface, being adhered thereto and the surrounding substrate. Moistureis of course also evaporated from the cellulose substrate during theindicia drying, and the water content of the dried indicia-containingflat cellulose casing 23 discharged from the second drier 68 may beabout 14 wt..% H₂ O (bone dry basis). This is about the same moisturecontent as the casing 11 unwound from reel 10. As previously explained,the purpose of further moisturizing system 12a-12b is to add sufficientwater to compensate for that loss in drier 68. This moisture level (andadditional moisture) is needed if the indicia-containing casing 23 is tobe shirred. It is also preferred for maintaining physical integrity ofthe cellulose casing during the various processing steps of theflexographic printing system. This will avoid cracking or breakingbecause of excessive rigidity on one hand, and yet the cellulose casingwill not contain so much moisture as to be non-self supporting.

The dried indicia-containing flat cellulose casing 23 discharged fromsecond drier 68 is hot and may for example be at 60°-80° C. It isdirected by guide roll 24 for transport around chill roll 25 for coolingby cold water jacket 26 to relieve thermal stresses. The so-cooled,dried indicia-containing flat casing 27 is rewound on roll 28 forstorage until needed for further processing, preferably includingshirring, prior to transport to customer packing houses.

The above-described printing system is for the preparation of an articlewherein the bottom surface of the colorant layer is in contiguousassociation with the substrate, that is, the indicia comprises twolayers, a colorant under layer and a binder-sealant over layer. Aspreviously explained, another article of this invention has a firstbinder-sealant layer with its bottom surface adhered to the substrate.The under surface of the colorant layer is superimposed on the topsurface of the first binder-sealant layer in adhering and nondiffusiblerelationship therewith. A second binder-sealant layer comprises thebinder-sealant superimposed over the colorant layer. The firstbinder-sealant also has a melting point above about 100° F. and is watersoluble. For this embodiment another binder-sealant application systemis needed, and the above-described system comprising elements 15bthrough 19b would be suitable along with second drier 68. This systemwould be placed upstream the colorant application system 15a through 19aand downstream unwind reel 10.

FIG. 1B illustrates an embodiment of the invention article comprisingcellulose substrate 80b having thereon a desired overlay-type indiciaentirely surrounded by the substrate. The indicia in turn comprises awater soluble dry colorant underlayer 81b in nondiffusible associationwith the substrate, and a binder-sealant layer 82b superimposed over andentirely enclosing the colorant layer top surface in adheringrelationship with the colorant layer top surface. The perimeter of thebinder-sealant layer 82b outwardly extends beyond the extremities of thecolorant layer so as to directly contact the surrounding substrate 80bin adhering relationship therewith. This covering and enclosing functionof the binder-sealant portion of the indicia is essential to isolate thecolorant portions of the indicia from the surrounding environment. Thelatter includes moisture, and without the protective enclosing cover thewater soluble colorant layer would be at least partially dissolvedeither during handling and storage of the indicia-containing article, orduring attempted transfer to the outer surface of the food body.

To perform its protective enclosing function, the binder-sealant isformed of material which is water insoluble. Moreover, thebinder-sealant material has a melting point above about 100° F., whichrepresents the warmest ambient temperature to be encountered in handlingand storage. This is because the binder-sealant must be physicallystable and able to perform its function as the colorant enclosure untilplaced in contact with the edible food surface for the desired transferof the complete indicia.

FIG. 1C illustrates the outer surface of the processed meat body alongwith the transferred FIG. 1B indicia. As will be subsequentlydemonstrated, for some combinations of substrate-indicia-meat body thetransfer may occur by contacting the indicia with a meat body outersurface which has already been processed, but this Figure shows thefunctional relationship between the various constituents for anindicia-containing meat body wherein the indicia transfer occurs duringprocessing. The binder-sealant 82c has penetrated the meat body outersurface 83c into the body itself, and soluble proteins from the meatbody have migrated into the transferred colorant layer 81c. Theseproteins are denatured during the thermal processing and at leastphysically bond or adhere the colorant to the processed meat. There mayalso be a chemical reaction between the denatured proteins of the meatand the colorant depending on the type of colorant used. For example,the carbohydrate portion of caramel probably engages in a Maillard-typereaction with the meat proteins. Whatever the mechanisim, the bond issufficient to prevent loss of the water soluble caramel when the caramelindicia-containing processed meat body outer surface is contacted withmoisture.

For physical comparison purposes, the cellulose substrate-supportedindicia of FIG. 1B is sufficiently thick to be felt by rubbing one'shand across the substrate, but the transferred indicia of FIG. 1C hassufficiently penetrated the meat body during processing so that it maynot be located by hand rubbing.

FIG. 1D illustrates another embodiment of the invention articlecomprising cellulose substrate 80d having thereon a desiredsandwich-type indicia entirely surrounded by the substrate. The indiciain turn comprises a first binder-sealant layer 84d with its bottomsurface adhered to the substrate 80d, a water soluble dry colorant layer81d with its under surface superimposed on the top surface of the firstbinder-sealant layer 84d in adhering and nondiffusible relationshiptherewith, and a second binder-sealant layer 82d. The latter issuperimposed over the colorant layer 81d top surface and extends beyondthe colorant layer extremities in adhering relationship therewith so asto entirely enclose the colorant layer. The outer perimeter of at leastone of the first binder-sealant layer 84d and the second binder-sealantlayer 82d outwardly extends beyond the colorant layer extremities so asto directly contact the surrounding cellulosic substrate 80d in adheringrelationship for the same reasons discussed in connection with theoverlay-type indicia FIG. 1B. That is, FIG. 1D shows the perimeters ofboth the first and second sealant-binder layers (84d and 82drespectively) adhered to the surrounding substrate 80d, but this is notessential. For example, the first sealant-binder layer 84d outerperimeter may be coextensive with the colorant layer 81d outerperimeter, and also entirely enclosed by the superimposed secondsealant-binder layer 82d outer perimeter which is adhered to thesurrounding substrate 80d. Conversely, the second sealant-binder layer82d outer perimeter need only enclose the colorant layer 81d outerextremities and merge outside the colorant layer with the firstsealant-binder. In this embodiment the latter extends beyond thecolorant layer 81d perimeter and is adhered to the surrounding substrate80d.

FIG. 1E illustrates the outer surface of the processed meat body alongwith the transferred FIG. 1D indicia. As with the FIG. 1C transferredindicia, the FIG. 1E indicia has been transferred during hightemperature processing of the meat body to the latter's outer surface83e. The second binder-sealant 82e has penetrated the meat body outersurface 83e into the body itself, and as previously described inconnection with FIG. 1C, the migrated soluble proteins from the meathave denatured and at least physically bonded the colorant 81e to thisprocessed meat. The first binder-sealant 84e is still adhered to thecolorant (now its outer layer) and has also migrated to the surroundingmeat outer surface and is also bonded by the migrated denatured proteinsto the meat body. The first binder-sealant 84e is preferably transparentas the latter covers and encloses the colorant outer surface.Accordingly, the colorant layer 81e is visible through the preferablytransparent first binder-sealant layer 84e.

Although the FIG. 1E sandwich-type embodiment of the indicia-containingfood body has been described and illustrated as comprising threedistinct layers, in practice the layers may not always be visuallydistinct because of their extreme thinness and the aforedescribed meatprotein migration. However, it is apparent that they are functionallyintact because of their reverse order transfer from the substrate duringfood processing.

FIG. 2 illustrates one casing embodiment of the article aspect of thepresent invention wherein the indicia 30 is formed of a dry colorantunder layer and a binder-sealant cover layer. As shown, the indicia 30is in the form of a repeated ordered indicia bonded to and extendingalong the casing exterior surface 31. The repeat and order derives fromapplying the indicia onto casing exterior surface 31 as the casing 14moves at a relatively constant speed across a printing wheel 18 rotatingat the same speed (FIG. 1A). The particular indicia illustrated in FIG.2 is composed of a plurality of short parallel line segments 32 disposedtransverse the longitudinal axis 33 of the casing to simulate grillmarks.

The grill marks 32 are disposed on a surface of the casing adapted tocome into direct with the food product stuffed into the casing. Sincethe indicia 30 is disposed on an exterior surface 31 of the casing andis substantially nondiffusible into and through the casing wall, thecasing must be inverted either before or during stuffing to locate thepattern 30 on the inside of the casing.

FIGS. 3 and 4 illustrate alternative methods for shirring theindicia-containing casing illustrated in FIG. 2. In FIG. 3, reel 28 fromFIG. 1A comprises indicia- containing casing article 27 having indiciacomposed of a pattern of grill marks 32 on its outer surface. Casingfrom this reel is unreeled and fed directly to a conventional shirringmachine generally indicated at 29. Shirring proceeds in a conventionalmanner in that the casing article 27 is inflated and fed onto a mandrel34. The casing passes along the mandrel and through a conventionalshirring head 35 which gathers the casing into pleats and forms ashirred stick indicated at 36. The shirring mandrel 34 is hollow so thatan aqueous shirring solution can be delivered as a spray 37 to theinterior of the casing. As mentioned hereinabove, a conventionalshirring solution includes a water phase. This is applied in an amountsufficient to rehumidify the casing in order to raise the moisturecontent from about the 14% level of the reeled casing to a levelsuitable for shirring and stuffing, i.e. in the range of about 20% toabout 38% moisture (based on bone dry cellulose) for nonreinforcedcasing. In the shirring method as shown in FIG. 3, the total moistureadded by the shirring solution would be about 12% to 14% in order toraise the casing moisture content from about the 14% level of the reeledcasing to preferably about 26% to 28% (bone dry basis).

The shirred stick 36 formed in this fashion contains casing having theindicia e.g., pattern of grill marks 32, on an outside surface.Accordingly, this stick would be inverted during stuffing so as tolocate the pattern of grill marks 32 on the inner surface (i.e. the foodcontacting surface) of the casing. Inversion during stuffing ("reversestuffing") is accomplished by turning and passing the casing through thebore of the stick as generally shown, for example, in U.S. Pat. Nos.4,292,711 and 4,162,693.

During reverse stuffing the stick end closure is pushed through theentire length of the stick, as shown for example in U.S. Pat. No.4,292,711. For this reason an end closure of the type disclosed in U.S.Pat. Nos. 4,759,100 and 4,693,280 is preferred, particularly such an endclosure having a relatively long plug of casing length which is nottightly compressed. The reduced compression plug results in an endclosure having a lower deplugging force through the stick bore. Anotherpreferred feature of a reverse stuffing system is a low frictionstuffing horn such as one having a "Teflon" coated surface to reducedrag during movement of casing across the surface.

Shirred sticks for the production of frankfurters are usually twistedduring shirring to improve the straightness of the stick as disclosedfor example in U.S. Pat. Nos. 3,398,069 and 4,649,961. When usingreverse stuffing and a stuffing machine of the type shown in U.S. Pat.No. 3,115,668 (FAM Machine) to produce frankfurters, there is apreferred direction of twist. In this respect, the FAM Machine rotatesthe shirred stick about the stuffing horn during stuffing. For reversestuffing it is preferred to use a stick which has been twisted, duringthe preceding shirring step, in a direction which is opposite to thedirection of the rotation of the stick on the stuffing horn of the FAMMachine. This opposite direction of stick twist will counteract atendency of the deshirred casing (passing through the bore of the stick)to twist about the stuffing horn. Unless counteracted, the twisting ofthe deshirring casing about the stuffing horn may cause the casing tobind and seize to the horn and break.

During reverse stuffing it is also preferred to maintain a clearancebetween the stuffing horn and the inner peripheral surface of the stick.This will provide a clear passage for the deshirring casing and furtherhelp to avoid binding of the deshirred casing to the horn. Maintaining aclearance space is accomplished preferably by a thrust collar which ispositioned around and pressed axially against the deshirring end of therotating shirred stick. Such a thrust collar will maintain coaxialalignment of the stuffing horn and a shirred stick, and avoid eccentricrotation of the stick about the horn. The FAM Machine has a followerwhich pushes against the end of the shirred stick. Modifying thisconventional follower to receive a thrust collar for purposes describedhereinabove is well within the skill of the art and the thrust collarper se forms no part of the present invention.

It should be appreciated that the deshirring force for reverse stuffingis substantially higher than for conventional stuffing, so that in aparticular reverse stuffing system it may be desirable to reduce therequired force to avoid casing breakage. Those skilled in the art willappreciate that the deshirring force may, for example, be reduced byusing a surfactant such as one or more alkylene oxide adducts of fattyacids or fatty acid partial esters, e.g. "Tween 80" manufactured byAtlas Chemical Industries, Inc. or "Mazol 80" a product of MazerChemicals, Inc., in the shirring solution to form a surfactant layer onthe casing. For the same reason, surfactants are preferably also used inthe oil lubricant for the shirring wheel-casing outside surfaceinterface, e.g. 0.5 wt% Mazol 80 in mineral oil. Another approach tolower the deshirring force is the use of lower density shirring incompression (i.e., lower pack ratio) than the otherwise maximum valueobtainable. This will reduce the drag effect of the deshirring casingbecause a less tightly packed or compressed casing will deshirr moreeasily and with less force than a tightly packed casing. Still anothertechnique for reducing the deshirring force is to use shorter thanconventional shirred lengths which also reduces the drag effect as thedeshirring casing passes through the bore of the shirred stick.

On the other hand, the deshirring force should not be reduced to thelevel at which the shirred casing stick coherency is substantiallyreduced, as this would prevent normal handling without damage.

In one successful demonstration of reverse stuffing, a size 24 (1.26inch flat width) nonreinforced cellulosic casing was used to produce ashirred stick. The latter's pack ratio was 82, the shirred stick lengthwas 14 inches and a centering type thrust collar was used at the stickdeshirring end. This casing was stuffed at a commercial rate of about220 ft/min. with no casing breakage using a FAM Machine.

In FIG. 4, casing with the indicia on its outer surface is shirred as inFIG. 3 but preferably loosely. The resulting loosely shirred article 36'is then placed on a hollow mandrel 38. To prevent article 36' fromslipping off mandrel 38, a support member 55 is disposed at the end ofarticle 36'. The support member 55 may also be biased in a conventionalmanner (not shown) such as by air or spring means, so as to continuouslybe a support for shirred article 36' as it is being deshirred. Inaddition, a second support member 56 can be disposed at the opposite endof shirred article 36' thereby maintaining and fixing article 36'between members 55 and 56. Coupled to one end of mandrel 38 is an airsupply pump 39.

The end of the loosely shirred article 36' proximal the air supply endof mandrel 38 is deshirred and fed through the bore of the looselyshirred article 36' and transported over the opposite end 40 of mandrel38 where the casing becomes inflated through activation of the air pump39. As the end of shirred article 36' against support member 55 isdeshirred and fed through the bore of article 36', the length of thearticle will become progressively smaller. Support 55 is biased to theleft as shown by the arrows in FIG. 4 to maintain a supporting contactwith the shirred article. This support arrangement will effectivelyprevent shirred article 36' from slipping off the mandrel 38.

The inflated casing 41 now has the indicia 32' on its inner surface, andis reshirred by movement through second shirring machine 42. Afterpassing through squeeze rolls 43 shirring proceeds in a conventionalmanner by passing the casing through shirring head 44 which gathers thecasing into pleats and forms a shirred stick indicated at 45. Theshirring solution spray 46 is delivered through the outlet of mandrel47.

This loose shirring - inversion second shirring system is of the typedescribed in U.S. Pat. No. 4,162,557 and locates the indicia on theinside of the casing. Alternatively, the casing article 27 from reel 28(FIG. 1A) may be first unreeled, loosely shirred and cut from the supplyreel. These shorter shirred lengths are then inverted and rewound onto anew reel. The casing is then unreeled and fed directly to the secondshirring machine 42.

FIG. 5 illustrates a skinless frankfurter 48 made in the FIG. 2 casing.The frankfurter has a pattern on its outer surface derived from indiciamaterial applied to the casing in which the frankfurter was made. In theembodiment shown, the pattern simulates grill marks 32' in mirror imageto the pattern 30 on the casing (FIG. 2). It should be noted that thegrill marks are composed of the overlay or sandwich-type indiciaindelibly transferred to the frankfurter surface. As shown in FIG. 5,the grill marks 32' are restricted substantially to the frankfurtersurface 49 and the coloring material does not to any significant extentdiffuse into the body 50 of the frankfurter beneath the surface.

FIG. 6 illustrates a flat cellulose casing 51 having on its outersurface, indicia in the form of a corporate logo 52 with adjacent logoslongitudinally spaced from each other and formed in the mirror image ofthe desired indicia.

FIG. 7 illustrates a skinless frankfurter 53 made using the casingembodiment of FIG. 6. Here the frank- furter carries the indiciacomprising a corporate logo 52' which is in mirror image to the logo 52on the casing 51.

Colorant

Although many types of colorants are functionally suitable for use inthis invention, there are stringent governmental restrictions on thisselection because the indicia formed therefrom is directly adhered to anedible surface. Accordingly, the selected colorant must be suitable forhuman consumption, and in the U.S. must be certified as "food approved"by the Food and Drug Administration. Organic dyes in this category aregenerally referred to as "FD&C" types, and the following Table A is acurrent list of the FD&C colors.

                  TABLE A                                                         ______________________________________                                        FD & C Colors                                                                 Designation                                                                            Common Name  Chemical Name                                           ______________________________________                                        Red      Erythrosine  Disodium salt of                                        No. 3                 9(o-carboxyphenyl)                                                            6-hydroxy-2, 4, 5, 7-                                                         tetraiodo-3H-xanthen-3-one.                             Red      None         Disodium salt of 6-hydroxy-                             No.40                 5-[(2-methoxy-5-methyl-4-                                                     sulfophenyl)azo]-2-                                                           naphthalenesulfonic acid.                               Yellow   Tartrazine   5-oxo-1-(p-sulfophenyl)-4-                              No. 5                 [(p-sulfophenyl)azo]-2-                                                       pyrazoline-3-carboxylic                                                       acid, trisodium salt                                    Yellow   Sunset Yellow                                                                              Disodium salt of 1-p-                                   No. 6    FCF          sulfophenylazo-2-naphthol-                                                    6-sulfonic acid.                                        Green    Fast Green   Disodium salt of 4-{[4-(N-                              No. 3    FCF          ethyl-p-sulfobenzyl amino)-                                                   phenyl]-(4-hydroxy-2-                                                         sulfonium phenyl)-                                                            methylene}-[1-(N-ethyl-N-                                                     p-sulfobenzyl)-Δ.sup.2,5 -                                              cyclohexadienimine].                                    Blue     Brilliant Blue                                                                             Disodium salt of ethyl                                  No. 1    FCF          [4-[p[ethyl                                                                   (m-sulfobenzyl)                                                               amino]-a-(o-sulfophenyl)                                                      benzylidene]-2,5-cyclohexad                                                   ien-1-ylidene]                                                                (m-sulfobenzyl) ammonium                                                      hydroxide inner salt.                                   Blue     Indigotine   Disodium salt of 5,5'-                                  No. 2                 disulfo-3-3'-dioxo-Δ.sup.2,                                             2'-biindoline.                                          ______________________________________                                    

It will be appreciated by those skilled in the art that secondary colorsmay be prepared from the above-listed primary colors to form an organicdye of virtually any desired tint. The resulting secondary color dye maythen be used to form an indicia of the desired color. For example,following is a representative list of brown-type colors which may beformulated by blending FD&C dyes:

    ______________________________________                                        Shade          FD & C Dye % Blend                                             ______________________________________                                        Butterscotch   Yellow #5  74                                                                 Red #40    24                                                                 Blue #1     2                                                  Chocolate      Red #40    52                                                                 Yellow #5  40                                                                 Blue #1     8                                                  Caramel        Yellow #5  64                                                                 Red #3     21                                                                 Yellow #6   9                                                                 Blue #1     6                                                  ______________________________________                                    

Alternatively, brown FD&C dye may be purchased in the premixed form.

Caramel is the preferred colorant in the practice of this invention,primarily because of its relatively high molecular weight compared toother suitable colorants. For example, most caramels have averagemolecular weights in the 2600-5000 range whereas FD&C dyes havemolecular weights in the 450-800 range. This relatively high molecularweight is advantageous because the high viscosity inhibits the flow ofthe colorant during the necessary processing steps in the practice ofthis invention thereby reducing the possibility of loss from the desiredindicia to surrounding surfaces.

Caramel is a brown to black liquid or solid having the characteristicodor of burnt sugar and a pleasant bitter taste. At normal usage levelsit has little or no taste, however. Caramel is prepared by thecontrolled heat treatment of the following food-grade carbohydrates:dextrose, invert sugar, lactose, malt syrup, molasses, starchhydrolysates and fractions thereof, and sucrose. Various food-gradeacids, alkalies, and salts may be used to assist caramelization. Fromthe physical standpoint, caramel consists essentially of coloidialaggregates which are soluble in water but only partly soluble inalcohol-water solutions.

Caramels are classified by caramel manufacturers in terms of theircolors, based on constituents used to assist caramelization. Theseclasses are as follows:

Class I--Plain Caramel Color,

Class II--Caustic Sulfite Caramel Color,

Class III--Amonia Caramel Color,

Class IV--Sulfite-Amonia Caramel Color

The molecular weight distributions of the four classes of caramel are asfollows:

                  TABLE I                                                         ______________________________________                                        Molecular Wt..sup.1                                                                      Class I  Class II  Class III                                                                            Class IV                                 ______________________________________                                        Below 2,000                                                                              --       87%       64%    55%                                      2,000-10,000                                                                             --       10%        4%    15%                                      Above 10,000                                                                             --        3%       32%    30%                                      Arithmetic Avg..sup.2                                                                             --        2600   4700                                     5000                                                                          ______________________________________                                         .sup.1 Information from Sethness Products Company                             .sup.2 Arithmetic average determined with values of 2,000, 6,000 and          10,000 for the above three ranges                                        

Binder - Sealant

The binder-sealant performs several functions in this invention.Firstly, it serves to bond the colorant layer to the substrate in thedesired indicia. As the colorant is water soluble, the binder-sealantmust be water insoluble to prevent smearing of the colorant during thesubstrate-to-food transfer (in the presence of moisture). When dried byevaporation of the organic solvent, the binder-sealant must form aphysical bond to both the colorant (as a cover enclosing the colorantlayer top surface) and the substrate. As previously explained, thebinder-sealant perimeter outwardly extends beyond the colorant layerextremities so as to directly contact the substrate in adheringrelationship. Also, the binder-sealant must seal the colorant fromcontact with water. In this manner, the binder-sealant protects thewater soluble colorant against water dilution (or even complete removal)during both storage of the indicia-containing substrate in a moisturizedatmosphere and subsequent food contact and processing in a moisturizedwater environment.

A further requirement of the binder-sealant is that it must be retainedon the outer surface of the substrate, and not migrate into thesubstrate interior. If this were to occur, the binder-sealant wouldprobably carry a portion of the water soluble colorant under thesubstrate surface and it would be difficult if not impossible tosubsequently transfer this portion of the colorant to the ediblesurface. For this reason, it is preferable to use relatively highmolecular weight material as the binder-sealant, which is too big tophysically enter the substrate interior.

A still further requirement of the binder-sealant is that it must becapable of substantially complete transfer from the substrate to acontiguous edible surface in the presence of moisture, and carrying thecolorant in this transfer. In many end uses of the inventive article,this transfer occurs during elevated temperature processing, i.e.cooking of the food body while encased in the aforementioned substratein the form of a casing. However, it has been discovered that with atleast certain embodiments the transfer from the substrate to an ediblesurface may be effected at ambient temperature.

The mechanism of the substrate-to-edible surface transfer is not fullyunderstood but is probably due to a difference in the bonding forcesbetween the substrate and the dried colorant, binder-sealant coveringindicia or colorant, binder-sealant sandwich indicia ("substratebonding") on one hand, and between the edible surface and the driedindicia ("edible surface bonding") on the other hand. Apparently, theedible surface bonding sufficiently exceeds the substrate bonding forsubstantially complete transfer of the indicia from the substrate to theedible surface. As used herein, "substantially complete transfer" meansthat the transferred indicia covers substantially the entire area ofedible surface in contiguous contact with the area covered by theoriginal indicia on the substrate. It does not necessarily mean thatsubstantially all of the layered colorant and binder-sealant forming theindicia is transferred from the substrate to the edible surface.

The preferred binder-carriers in the practice of this invention areshellac and zein. Shellac is an insect- exudate from Asia, and zein iswater insoluble prolamine protein from corn gluten. Shellac is preferredbecause of slightly superior transfer properties. Other suitablebinder-sealants may include nitrocellulose lacquers, vinyl lacquers,acrylic vinyls and polyamides, probably in modified form. Certain ofthese vehicles by themselves do not appear to provide all of therequired and preferred characteristics for use as binder-sealants in thepractice of this invention. That is, they do not facilitatesubstantially complete transfer from the substrate to the ediblesurface, or they do not completely provide the sealant or binderfunctions. However, these deficiencies can probably be overcome by theuse of other resin or plasticizer modifiers as for example ethylenevinyl acetate resin, polyester resin, dibutyl phthalate plasticizer ortricresyl phosphate plasticizer.

Substrate

The substrate, to which the desired indicia is bonded is preferablynonporous. That is, the substrate is preferably substantiallyimpenetrable by the aforementioned indicia. If the substrate is porous,the mixture in part enters the substrate inner body. Using onlycontiguous contact under conventional processing conditions for edibles,it then becomes more difficult to withdraw substantially all of theindicia from the substrate inner body and transfer same as part of theindicia from the substrate to the contiguous edible surface. Also,during elevated temperature processing, a flowable food such as anemulsion may in part enter the substrate main body and form a strongbond preventing separation of the porous substrate and theindicia-containing food body.

The substrate should preferably be flexible. This means that it shouldbe capable of contouring to the colorant or sealant-binder dispensingprinting surface (as for example a roller), for indicia depositionthereon in a substantially uninterrupted manner. Then the so-contouredindicia containing substrate must retain its physical integrity inassuming a possibly different contour or contours for handling andstorage, e.g. in flat form until needed for indicia transfer to thecontiguous edible surface. Since the latter is not necessarily itselfflexible, the indicia-containing substrate should preferably be able toassume a possibly still different contour for the edible surfacecontiguous contact necessary to substantially completely transfer theindicia to the edible surface.

To assure flexibility, certain types of substrates require plasticizers.For example cellulosic substrates such as food casing must includeplasticizer, most commonly polyhydric alcohols such as glycerine. Othersubstrates as for example thermoplastic films may not require a separateplasticizer compound for flexibility.

The substrate is preferably smooth surfaced to both assure that thecolorant layer or the binder-carrier layer(s) contact substantially theentire substrate surface for bonding thereto, yet can be substantiallycompletely transferred therefrom to the contiguous edible surface. Ifthe substrate has substantial texture the indicia may only contact theridges and not flow to the craters, leaving the low crater portionsuncolored. The same deficiencies in the substrate indicia may then betransferred to the edible surface. Even if the solution reaches thecraters of a textured surface, this portion of the indicia may notintimately contact the edible surface, resulting in less-than-completetransfer. On the other hand, it should be recognized that for someedible surface indicia the color need not be perfectly continuous butinstead in the form of colored sections at least partially surrounded byuncolored sections. An example of the latter is the so-called "process"type of printing in which the indicia color comprises small dotssurrounded by uncolored background.

Although the preferred substrate is cellulose casing, other materialsare suitable as for example a substrate formed from a thermoplasticfilm, preferably in the form of a casing. The film may for example beethylene vinyl acetate (EVA), a copolymer of vinyl chloride andvinylidene chloride (saran), or polyethylene. The latter broad categoryincludes for example, high density polyethylene, medium densitypolyethylene and low density polyethylene, as these sub classificationsare understood by those skilled in the art. Another preferred type ofpolyethylene is a copolymer of ethylene and an alpha olefin havingbetween 3 and 8 carbon atoms, generally known as very low or ultra lowdensity polyethylene. Moreover, the film substrate may be the innermostlayer of a multilayer film which for example includes an oxygen barrierlayer as a core. Suitable well-known core layer materials includeethylene vinyl alcohol (EVOH), nylon, saran and a copolymer of vinylchloride and methyl acrylate (MA saran). If a multilayer film is usedwith a core layer, there are preferably at least three layers comprisingthe innermost substrate layer on which the indicia are printed, thecore-barrier layer and an outer layer preferably selected to providehigh resistance to puncture and abuse. Suitable materials for theoutermost layer include EVA and the various polyethylenes.

Edible Surface

The edible surface to which the indicia is transferred may be primarilycarbohydrate such as pie dough or bread, or protein such as frankfurter,ham or poultry such as turkey. The edible surface may also be mixturessuch as turkey- bologna lunch meat. The edible surface may also beprotein such as cheese.

Transfer in Presence of Water

Either or both the indicia substrate and the edible surface must containwater moisture or the transfer must be in a highly water moisturizedenvironment. This requirement is most conveniently satisfied by thewater moisture in edible bodies. Moisture is needed because the indiciais at least partially permeable and moisture appears to be uniquely ableto penetrate the indicia and weaken the indicia colorant orbinder-sealant bonding to the substrate.

Indicia Transfer

For certain embodiments of the indicia substrate-to- edible surfacetransfer, the surfaces may be contacted at ambient temperature. The needfor elevated temperature substrate-edible surface contact for indiciatransfer depends on several considerations. These include the types ofsubstrate, edible surface, quantity of water present and desiredtransfer time. In general it is believed that for high speed commercialprocessing, the contact time should be minimized and with thisrequirement elevated temperature contact will be preferred. For completetransfer with minimum contact time, it is also preferred to have atleast 60% by wt. water in the edible surface. This will insure adequatelubrication to quickly release the dry indicia from the substrate andtransfer same to the edible surface.

The invention will be more clearly understood by reference to thefollowing non-limiting examples.

EXAMPLE 1

In this example, a series of tests were performed using smooth andpowdered thermoplastic film as the substrate with two different types ofcolorant (caramel and FD&C brown dye). In all instances, thebinder-sealant was shellac. Different types of edible foods were usedi.e. cheese (protein) and turkey (fowl). Also, the foods were used indifferent forms, i.e. lunchmeat, ground particles (fresh ground turkey)and large pieces (fresh turkey breast). Finally, the indicia transfertest was performed at both ambient temperature and food processingtemperature (180° F.).

More specifically, the substrate was an ethylene vinyl acetate (EVA)surface of a commercially employed irradiated multilayer film of about 2mils thickness. In one series of tests, the substrate film was smoothand in another series the substrate film contained powdered starch. Thefilms were not corona-discharge treated, even though such treatment isknown to improve the coating-to-film adhesion properties.

The caramel-containing aqueous solution was prepared by mixing 50 wt%caramel powder (type 858 manufactured by Sethness Products Co., Chicago,Ill.) in water, and this solution was applied to the film substrate by aflexographic hand proofer as a layer about 4 inches wide ×14 incheslong. After air drying for about 5 minutes, the dried caramel indiciaportion was about 0.03 mil thick.

The binder-sealant solution was prepared by mixing 20 wt% clear shellac(food grade "lac" dewaxed white type purchased from Bradshaw Praeger &Co., Chicago, Ill.) and 80 wt% normal propyl alcohol solvent. Thissolution was applied over the dried caramel layer top surface by aflexographic hand proofer so as to entirely enclose the caramel layertop surface and extend about 1/4 inch beyond the latter's outerextremities. This binder-sealant directly contacted the surrounding filmsubstrate. The solvent was air dried in a very short period--about 5seconds--and the shellac adhered to both the caramel top surface and thesurrounding film substrate. The thickness of this dried shellacbinder-sealant layer was about 0.04 mils. These caramelunderlayer-shellac overlayer indicia containing thermoplastic filmsubstrate articles were used in a series of indicia-to-food transfertests discussed hereinafter.

For another series of articles, brown FD&C dye was used as the colorant.This brown dye was prepared by mixing the following three FD&C dyes (allobtained from Warner-Jenkinson Co., St. Louis, Mo.) in the indicatedproportions: 30.5 wt% Yellow No. 6, 45.0 wt% Red No. 40, and 24.5 wt%Blue No. 1. Carboxymethyl-cellulose ("CMC") was used as a carrier forthe brown dye colorant; the procedure was to first dissolve the CMC inwater and prepare a 4% by wt. CMC-containing aqueous solution. The browndye was then added in dry form to the CMC-containing aqueous solution soas to comprise 15 wt% of the final solution. This mixture was thenapplied to the same EVA film substrate and dried in the same manner asthe aforedescribed caramel layer to provide an underlayer of about 0.03mil thickness. The same shellac-normal propyl alcohol solution wasapplied over the dried brown dye layer top surface in the aforedescribedmanner, followed by drying. The thickness of this dried shellacbinder-sealant overlayer was also about 0.04 mil. These brown dyeunderlayer-shellac overlayer indicia containing thermoplastic filmsubstrate articles were also used in a series of indicia-to-foodtransfer tests.

For the indicia transfer tests, a 4 in.² section of theindicia-containing film was placed on the edible food surface and thesecombinations wrapped in aluminum foil. The combinations were unwrappedafter 15 minutes at ambient temperatures and the indicia transfer wascomplete. For the elevated temperature indicia transfer tests, freshground turkey and fresh turkey breasts were used as the edible surfaceand the indicia-containing thermoplastic film was positioned incontiguous contact with the edible surface. The combinations werewrapped in aluminum foil and heated at 170°-180° F. for three hours tocook the meat. After cooking, the films were removed and the meat outersurfaces were examined immediately thereafter; indicia transfer wascomplete. These transfer tests are summarized in Table B.

                                      TABLE B                                     __________________________________________________________________________    Film-To-Meat Indicia Transfer                                                 Test                                                                              Film          Food   Transfer* Temp.                                      No. Surface                                                                              Colorant                                                                             Surface                                                                              Ambient                                                                             170°-180° F.                     __________________________________________________________________________    1-A Smooth Caramel                                                                              Turkey Yes   --                                                               Lunchmeat                                                   1-B Smooth Brown Dye                                                                            Turkey Yes   --                                                               Lunchmeat                                                   1-C Powdered                                                                             Caramel                                                                              Turkey Yes   --                                                               Lunchmeat                                                   1-D Powdered                                                                             Brown Dye                                                                            Turkey Yes   --                                                               Lunchmeat                                                   1-E Smooth Caramel                                                                              Processed                                                                            Yes   --                                                               Cheese                                                      1-F Smooth Brown Dye                                                                            Processed                                                                            Yes   --                                                               Cheese                                                      1-G Powdered                                                                             Caramel                                                                              Processed                                                                            Yes   --                                                               Cheese                                                      1-H Powdered                                                                             Brown Dye                                                                            Processed                                                                            Yes   --                                                               Cheese                                                      1-J Smooth Caramel                                                                              Ground --    Yes                                                              Turkey                                                      1-K Smooth Brown Dye                                                                            Ground --    Yes                                                              Turkey                                                      1-L Powdered                                                                             Caramel                                                                              Ground --    Yes                                                              Turkey                                                      1-M Powdered                                                                             Brown Dye                                                                            Ground --    Yes                                                              Turkey                                                      1-N Smooth Caramel                                                                              Turkey --    Yes                                                              Breast                                                      1-O Smooth Brown Dye                                                                            Turkey --    Yes                                                              Breast                                                      1-P Powdered                                                                             Caramel                                                                              Turkey --    Yes                                                              Breast                                                      1-Q Powdered                                                                             Brown Dye                                                                            Turkey --    Yes                                                              Breast                                                      __________________________________________________________________________     *Transfer was complete in all tests.                                     

Example 1 (and Table B) demonstrates several difficult aspects of thescope of this invention. For example, the three FD&C dyes comprising thetested brown dye mixtures are quite different chemically, as shown inTable A, yet they all transferred as part of the indicia to the meatsurface (although there was some chromatographing of color with theturkey lunchmeat with the passage of time). Moreover, caramel ischemically quite different from any of the tested FD&C colors.Accordingly, it has been shown that a wide variety of water solublecolorants are useful in the invention.

This Example also shows that at least some substrate-to-edible surfaceindicia transfers may be effected at ambient temperature, i.e. for atleast certain processed meats and cheese which do not require reheating.On the other hand, for edibles which require processing in a casing, theindicia may be transferred from the casing inner surface to thecontiguously associated edible surface during processing of the ediblebody in the casing. That is, no additional processing step is needed totransfer the indicia to the edible outer surface.

Example 1 further shows that indicia may be transferred to differenttypes and forms of edible surfaces. For example, complete transfer wasachieved to three different forms of turkey, i.e. lunchmeat, large sizemeat pieces (turkey breast) and small pieces of meat (ground turkey).Although only turkey was tested, it is believed indicia transfer wouldbe successful to other meats including different types of poultry, asfor example, chicken and duck, as well as ham and sausage emulsions. TheExample also demonstrates that indicia transfer may be accomplished withprotein-type edible surfaces, as for example, processed cheese.

This Example additionally shows that substantially complete transfer maybe obtained irrespective of whether the substrate is smooth surface ortextured, although the former is preferred for reasons discussed underthe heading "Substrate".

One preferred article of this invention comprises a shirredthermoplastic film casing having on a surface thereof as a substrate adesired indicia comprising a dry caramel layer with its bottom surfacein contiguous and nondiffusible association with the film surface. Abinder-sealant is superimposed over and entirely encloses the carameltop surface in adhering relationship, the binder-sealant perimeteroutwardly extending beyond the caramel layer extremities so as todirectly contact the surrounding film surface in adhering relationshiptherewith. In a preferred processable food package employing thisarticle, the casing is filled with water moisture containing processablefood having its water moisturized outer surface in direct contact withthe casing inner surface. The binder-sealant top surface is incontiguous association with the food outer surface.

For certain embodiments of this invention, it is preferred that theindicia be moisture insensitive, i.e. for end uses where the substrateitself must have a high moisture content or where the indicia transferoccurs in a high moisture atmosphere. As used herein, "MoistureInsensitive" means that the indicia will not separate from the substrateto any appreciable extent (as evidenced by significant discoloration ofthe collected water) when the indicia-containing substrate is held underrunning ambient temperature cold water from a faucet at rate of about 1U.S. gallon/minute for 30 seconds. This means that the indicia is notwater soluble. The indicia-containing substrates of Example 1 were notmoisture insensitive by this stringent standard. However, they wereconsiderably less moisture sensitive than the correspondingthermoplastic film substrate-colorant layer article without thebinder-sealant overlayer.

Also, for certain embodiments of this invention it is preferred that theindicia be bonded to the substrate in an abrasive resistant manner forreasons already discussed. As used herein "abrasion resistant manner"means that less than about 50% of the indicia surface area separatesfrom the substrate when subjected to the Dry Scratch Test (hereinafterdescribed). This performance standard is adequate when theindicia-containing substrate is to be used in a manner where the shearforces are minimal, as for example when the substrates are physicallystacked or rolled in overlying compressive relationship for storageprior to transfer to the edible surface. However, when theindicia-containing substrate is to be used in a manner where the shearand torsion forces are extremely high, as for example on shirredcellulose food casings, the mixture is more preferably bonded to thesubstrate as an indicia in a "high abrasion resistant manner". As usedherein "high abrasion resistant manner" means that the indicia will notonly satisfy the abrasion resistant preferred manner requirement, butalso that less than 50% of the indicia surface area separates from thesubstrate when subjected to the Wet Scratch Test (hereinafterdescribed).

Scratch Tests for Adhesion

The indicia-containing substrate is placed on a smooth flat surface andusing the backside of the investigator's index fingernail portion (withthe fingernail in a smoothed out, i.e. filed condition) at a contactangle less than about 30 degrees to the substrate surface, the entireindicia surface area is lightly scratched five (5) times (with a minimalforce). The surface area of any removed indicia material is measuredrelative to the total scratched surface. The surface measurements arebased on the substrate area from which indicia material has beenremoved, compared to the total area of the as-formed indicia.Measurements may for example be made by use of a planimeter. For the DryScratch Test there is no wetting. For the Wet Scratch Test, water issprayed on the underside (opposite the indicia-containing side) of thesubstrate as mist and in sufficient quantity to form a film. The scratchtest is performed immediately thereafter.

The test results may be numerically rated from 1 (excellent-no loss ofindicia) to 5 (very poor-complete loss of indicia). In this ratingsystem 2 is up to about 25% loss of indicia, 3 is between about 26% andabout 49% loss of indicia, and 4 is between about 50% and about 74% lossof indicia. This means that a rating of 1, 2 or 3 is acceptable from thestandpoint of abrasion resistance.

Tape Test and High Adhesion Bonding

To test adhesion of the indicia to the substrate, a commerciallyavailable transparent adhesion tape (#610 marketed by 3M Company) ishand pressed over the indicia, and then hand pulled away from theindicia--first at 90 degrees to the substrate and then at 180 degrees tothe substrate surface which is more severe. The tape adhesion surface isexamined for color and the indicia inspected for loss of color. Ifeither reveals significant removal of color from the indicia, the latteris deemed to have failed the test, and if there is no significantremoval of color the indicia passed the tape test. A most preferredembodiment of the inventive article has "high adhesion bonding" betweenthe substrate and the indicia, and this means the article passes theaforedescribed tape test.

Using the aforedescribed criteria, the indicia-containing substrates ofExample 1 did not provide abrasion resistance. This was not an objectiveof these experiments as the thermoplastic film substrate was notcorona-discharge treated prior to use. Based on prior art teachings, itis believed that such treatment would have improved abrasion resistance.

It has previously been stated that the substrate to which the desiredindicia is bonded is preferably nonporous. For this reason, it ispreferred not to use the uncoated paper side of fiber (paper) reinforcedcellulosic casing as the substrate. If such casing is to be used in thepractice of this invention, it is preferred to apply the indicia to theviscose coated side because the latter is relatively nonporous. This ofcourse is not a problem with nonreinforced cellulose prepared by theviscose-xanthation process, because each side of the casing isrelatively nonporous. Thermoplastic films are usually relativelynonporous.

EXAMPLE 2

In this example a brown logo type indicia-containing nonreinforcedcellulosic food casing was prepared in accordance with this invention,using commercial printing equipment.

The colorant comprised a 50 wt% caramel-containing aqueous solutionprepared by mixing caramel powder (Sethness type 858) in water (solutionviscosity 23 seconds as measured with Zahn cup No. 2). Thebinder-sealant was of two types. One type comprised 20 parts zein, 72parts isopropyl alcohol solvent and 8 parts water (all on weight basis).The viscosity of this zein binder-sealant solution was 28 seconds. Theother type comprised 30 wt% clear shellac and 70 wt% isopropyl alcoholsolvent. The viscosity of this shellac binder-sealant solution was 19seconds.

The casing used in this test was regular (no peeling aid) nonreinforcedcellulose casing manufactured by Viskase Corporation using theviscose-xanthation process, designated size 24 having 1.30 inch flatwidth. This casing was from a production lot but diverted from theproduction system prior to shirring.

The indicia to be printed on the casing outer wall was the star logo ofARMOUR® Company with the letters about 5/16-inch high and the star about5/16-inch high. The indicia repeated every 3 inches along the casinglength, with all indicia positioned on the same central axis as forexample illustrated in FIG. 6.

The printing apparatus used to apply the indicia was a flexographicpress system as generally illustrated in FIG. 1A. The printing procedurewas as previously described in connection with FIG. 1A, using separateprinting heads for the caramel underlayer and the binder-sealantoverlayer. The flat casing 14 fed to the colorant printing station hadabout 16 wt% water (bone dry basis). The caramel colorant layer portionof the indicia was dried to about 300° F. in first drier 60 and had athickness of about 0.03 mil. The solvent of the binder-sealant portionof the indicia was evaporated in second drier 68 at 300° F. to provide abinder-sealant layer thickness of about 0.04 mil so that the totalthickness of the overlaid indicia was about 0.07 mil.

It will be recognized that the moisture content of the driedindicia-containing cellulose casing 23 is affected by the casingthroughput rate, and for the shellac coated indicia-containing articlethe relationship were as follows: at 100 fpm, 8.5-9.0% H₂ O; 150 fpm,9.5-10.0% H₂ O; and 200 fpm, 10.7-11.0% H₂ O (all on bone dry basis).For the zein coated indicia-containing article the relationships were asfollows: at 100 fpm, 8.5% H₂ O; 150 fpm, 10.0% H₂ O; and 200 fpm,10-10.5% H₂ O.

The indicia-containing cellulosic casing prepared in the aforedescribedmanner was examined on the basis of the aforedescribed criteria and metall requirements. More specifically, the indicia resolution with eachtype of binder-sealant was excellent, and easily readable. Thebinder-sealant overlayer extended about 1/8 inch beyond the outerperimeter of the caramel under layer, and adhered to the cellulosesubstrate. The indicia abrasion resistance was not directly measured butwas functionally satisfactory because none of the indicia separatedduring the subsequent processing steps prior to transfer. Likewise, theindicia-to-substrate bond moisture sensitivity was functionallysatisfactory because despite exposure to moisture-containingenvironments there was no indicia separation prior to transfer to thefood surface.

The aforedescribed indicia-containing cellulose casing was then shirredand compressed to a pack ratio of about 82 using commercial equipment ofthe standard fixed mandrel type operated at a production rate of about1200 ft/min to produce shirred sticks. Sufficient moisture was added bythe shirr spray to increase the water content to about 26 wt.%. Duringshirring, the stick power-twist was oriented opposite to the FAMspinning direction in accordance with the aforereferenced U.S. Pat. No.4,649,961.

There was excessive breakage and pinholing of the casing duringshirring. Further work was needed to identify commercial operatingconditions for production of an indicia-containing casing withsufficient moisture in the as-dried article to avoid shirring damage andyet retain the high resolution of the indicia. A series of tests wereperformed for preparation of both the shellac and zein coated articlesto identify optimum operating conditions, by varying the dryingtemperature and the casing throughput rate. That is, to provide adequatemoisture for shirring without casing damage the drier temperature shouldbe relatively low and the throughput rate should be relatively high.Conversely, to insure a dry caramel colorant layer and avoid offsettingduring transfer to the food surface, the drier temperature should berelatively high and the throughput rate relatively low. For theparticular commercial system used in these experiments the optimumconditions for the zein coated article was a throughput rate of 125 fpmand a drier temperature of 250° F. For the shellac coated article theoptimum conditions were a throughput rate of 150 fpm and a driertemperature of 225° F. Shellac is preferred to zein as a binder-sealantfor caramel colorant because it is less sensitive to water and therebyprovides slightly better protection against indicia offsetting.

This Example demonstrates that the cellulosic food casing embodiment ofinvention article can be manufactured with commercial equipment at acommercial production rate.

This Example also demonstrates a preferred article comprising a shirringcellulosic food casing having on a surface thereof a desired indiciacomprising a dry caramel underlayer and a shellac binder-sealantoverlayer. The indicia was substantially completely transferable fromthe casing surface to the water moisturized outer surface of a food bodyduring processing thereof in the casing as demonstrated in the followingExample 3.

EXAMPLE 3

In this Example, the Example 2 brown indicia- containing shirredcellulose casings were used to produce frankfurter emulsion-containingpackages having the emulsion in direct contact with the indicia.

These shirred and reverse twisted casings were stuffed with acommercially available frankfurter meat emulsion formulation comprising50 lbs. beef chuck, 50 lbs. regular pork trim, 21/4 lbs. salt, 25 lbs.water, 1 lb. spice and 40 oz. Prague. The stuffing machine was theaforedescribed FAM type operated at about 220 fpm. casing and thestuffing horn was Teflon-coated. During stuffing the casing wasdeshirred and inverted through the bore of the stick so the casingturned inside out. This located the processable moisturized frankfurteremulsion in direct contact with the indicia.

This Example demonstrates that the frankfurter emulsion-cellulose casingprocessable food package embodiment of the invention can be preparedwith commercial equipment using a commercial production rate.

This Example also demonstrates a preferred processable food packagecomprising a cellulosic casing filled with water moisture-containingprocessable food having its water moisturized outer surface in directcontact with the casing inner surface, wherein the latter is a substratefor a desired indicia comprising a water soluble dry colorant layer asfor example caramel, with its bottom surface in contiguous andnondiffusible association with the casing inner surface, and a waterinsoluble binder-sealant layer as for example zein or shellacsuperimposed over and entirely enclosing the colorant layer top surfacein adhering relationship. The binder-sealant perimeter extends outwardlybeyond the colorant layer extremities so as to directly contact thesurrounding casing inner surface in adhering relationship therewith. Thebinder-sealant top surface is in contiguous association with the foodouter surface. The indicia is substantially completely transferable fromthe casing inner surface to the water moisturized food outer surfaceduring processing thereof in the casing, as demonstrated in thefollowing Example 4.

EXAMPLE 4

In this Example, the Example 3 frankfurter emulsion-indicia containingcellulose casing packages with caramel underlayer and either shellac orzein overlayer were used to produce frankfurters with the desired brownlogo indicia on their outer surface.

The aforedescribed packages were cooked in a smoke house at 180° F.using 25% relative humidity until the internal temperature reached 160°F., then water showered for 10 minutes for cooling to about 40° F. Thecasings were then hand-peeled.

During hot processing, the indicia simultaneously substantiallycompletely transferred from the casing inner surface to themoisture-containing frankfurter outer surface. This was apparent becausevisual inspection of the frankfurter outer surface revealedsubstantially complete coverage of the indicia contact area by the browncolor with each binder-sealant. Moreover, the indicia definition on thefrankfurter surface was very clear, although the color was somewhat lessbright than the original indicia on the cellulose casing outer surface.Examination of the peeled casings revealed substantially completetransfer of the indicia from the casing surface to the frankfurtersurface. There was no loss of indicia when the latter was hand-rubbed onthe frankfurter surface.

In other tests with substantially identical processed packages, thecasing was peeled from the frankfurter surface by a commercial-type(Apollo Ranger) peeler at speed of about 500 fpm, and the indiciaremained undamaged on the frankfurter surface.

This Example demonstrates that the logo indicia-containing frankfurteredible food embodiment of the invention can be prepared with commercialequipment using a commercial production rate.

This Example also demonstrates a preferred edible food productcomprising a frankfurter having on its outer surface a desired indiciaof either shellac or zein binder-sealant layer bonded to the frankfurterouter surface and caramel colorant adhered to the outer surface of thebinder-sealant.

EXAMPLE 5

The advantages of this invention were illustrated by comparable ARMOUR®star indicia-cellulose casing substrate tests using caramel indiciawithout a binder-sealant overlayer. That is, all other materials,compositions and treatments were identical to the aforedescribedExamples 2-4.

In the stuffing test, severe bleeding and offsetting was observed withrespect to the caramel-only indicia transferred to the processedfrankfurter surface. This striking difference between the transferredindicia was solely attributable to the binder sealant layer.

EXAMPLE 6

In this Example, a grill mark type indicia-containing nonreinforcedcellulosic food casing article was prepared and successfully shirredcasing a zein-caramel-zein sandwich type indicia.

The caramel colorant aqueous mixture and the zein binder-sealantmixtures were prepared using the same mixing proportions described inExample 2, and the substrate was the same type of nonreinforcedtransparent cellulosic casing used in Example 2 except thatcarboxymethyl cellulose (a peeling aid) was applied to the externalsurface prior to shirring. The indicia indicia were brown grill marksabout 1/8 inch wide, about 1 inch long and about 1 inch apart, asillustrated in FIG. 2. The above-described printing system used inExample 1 was also used to prepare the sandwich-type indicia, exceptthat another binder-sealant applicator system and drier was used betweenunwind reel 10 and colorant application system 15a-18a (see FIG. 1A).The last applied binder-sealant system was sized to apply a secondbinder-sealant layer whose perimeter extended outwardly beyond the firstbinder-sealant and colorant layer extremities so as to directly contactthe surrounding cellulosic substrate. This extension was about 1/8 inchbeyond the extremities of the underlying layers.

The indicia application system was operated at two different throughputrates (150 fpm and 200 fpm) and two different drier temperatures (225°F. and 275° F.). The combination of 150 fpm and 225° F. was preferred onthe basis that the indicia application system at these conditionsremoved the least amount of casing moisture (i.e. 11.5 wt% H₂ O incomingand 10.0% H₂ O outgoing) and there was no offsetting of the indiciathrough the shirring step. The latter was performed without casingdamage in the same manner as described in Example 3.

This Example illustrates the preparation of the article embodimentcomprising a cellulosic substrate having thereon a desired indiciacomprising a water insoluble first binder-sealant layer with its bottomsurface adhered to the cellulose substrate, a water soluble dry colorantlayer with its under surface superimposed on the top surface of thefirst binder-sealant layer in adhering and nondiffusible relationshipwith the last-mentioned layer, and a water insoluble secondbinder-sealant layer superimposed over the colorant layer upper surfaceand extending beyond the colorant layer extremities in adheringrelationship so as to entirely enclose the colorant layer. In thisExample the superimposed second binder-sealant layer extended beyond thecolorant layer extremities so as to directly contact the cellulosesubstrate. The Example also illustrates a preferred embodiment of thearticle wherein a peeling aid coating on the cellulose substrate isprovided beneath the first binder-sealant layer bottom surface.

EXAMPLE 7

The shirred zein sandwich type indicia-containing cellulose casingarticle of Example 6 was reverse-stuffed with frankfurter emulsion,processed and peeled, all in the same manner as described in Example 4.

Inspection of the grill mark indicia-containing frankfurters revealedthat a slight degree of offsetting had occurred even on the frankfurtersprocessed in the casing where offsetting had not occurred on theas-printed cellulose casing substrate. The offsetting was previouslyobserved on the shirred sticks, so was due to moisture penetration fromthe shirring solution. This slight offsetting could probably beeliminated by adjusting the indicia application process conditions, i.e.lower throughput rate and/or higher drying temperature.

This Example illustrates a processable food package embodiment of theinvention including a cellulosic casing filled with watermoisture-containing processable food having its water moisturized outersurface in direct contact with the casing inner surface. The latter is asubstrate for a desired indicia comprising a water insoluble firstbinder-sealant layer with its bottom surface adhered to the casing innersurface, a water soluble dry colorant layer with its under surfacesuperimposed on the top surface of the first binder-sealant in adheringand nondiffusible relationship therewith, and a water insoluble secondbinder-sealant layer superimposed over and entirely enclosing thecolorant layer upper surface in adhering relationship so as to entirelyenclose the colorant layer. At least one of the first and secondbinder-sealant perimeters outwardly extends beyond the colorantextremities so as to directly contact the surrounding casing innersurface in adhering relationship therewith.

Example 7 also illustrates a method for making an indicia-containingfood product according to this invention, employing a sandwich-typeindicia. A casing article is provided having a plasticized flexibleinner surface with an indicia comprising a water insoluble firstbinder-sealant layer having its bottom surface adhered to the casinginner surface in nondiffusible association therewith. A water solubledry colorant layer is superimposed with its under surface on the topsurface of the first binder-sealant layer in adhering and nondiffusiblerelationship therewith. A water insoluble second binder-sealant layer issuperimposed over the colorant upper surface and extends beyond thecolorant layer extremities in adhering relationship so as to entirelyenclose the colorant layer. At least one of the first and secondbinder-sealant perimeters extends outwardly beyond the colorantextremities so as to directly contact the surrounding casing innersurface in adhering relationship. The casing is filled with watermoisturized processable food such that the latter's outer surface is indirect contact with the second binder-sealant layer. The food-containingcasing is processed at elevated temperature to cook the food andsimultaneously substantially completely transfer the firstbinder-sealant, colorant, second binder-sealant sandwich indicia fromthe casing inner surface to the water moisturized processed food outersurface. The casing is peeled from the indicia-containing processed foodouter surface, yielding the food product.

This Example also illustrates an edible food product embodimentcomprising a processed food body having on its outer surface a desiredindicia sandwich of a water insoluble first binder-sealant layer, awater soluble colorant layer and a water insoluble second binder-sealantlayer. The top surface of the second binder-sealant layer is adhered tothe food body outer surface, the upper surface of the colorant layer isadhered to the second binder-sealant layer bottom surface, and the topsurface of the first binder-sealant layer is adhered to the colorantlayer under surface.

EXAMPLE 8

In this Example, a grill mark type indicia-containing nonreinforcedcellulosic food casing article was prepared and successfully shirred,using a shellac-caramel-shellac sandwich type indicia.

The caramel colorant aqueous mixture was prepared using the sameproportions described in Example 2. The binder-sealant mixture comprised23% shellac and 77% isopropyl alcohol solvent, with a viscosity of 10seconds. The substrate was the same type of nonreinforced cellulosiccasing with a CMC peeling aid coating on the outer surface, as used inExamples 2 and 6. The indicia were the same brown grill marks and theshellac-containing sandwich indicia was formed on the casing outersurface in the same manner as the zein-containing sandwich indicia inExample 6, using the same equipment.

The shellac indicia-forming processing conditions were also varied inthe same manner as the zein conditions, i.e. at 150 and 200 fpmthroughputs, with 225° and 275° F. drier temperatures. Typical moisturecontents for the cellulose casing were 14.1 wt% H₂ O before and 10.7% H₂O after indicia formation at 200 fpm throughput and 225° F. drying. Theshellac-containing sandwich indicia type casing article was shirred inthe same manner as the zein-containing sandwich indicia type casingarticle, and there was no casing damage nor offsetting.

EXAMPLE 9

The shirred shellac sandwich type indicia-containing cellulose casingarticle of Example 8 was reverse-stuffed with frankfurter emulsion,processed and peeled, all in the same manner as described in Example 4.

Inspection of the shellac sandwich grill mark indicia-containingfrankfurters revealed that even less offsetting had occurred than withthe zein sandwich grill marked frankfurters of Example 7.

Under equivalent manufacturing conditions, it appears that the sandwichtype indicia embodiment has slightly less offsetting on the food productsurface than the corresponding colorant underlayer binder-sealantoverlayer indicia embodiment of the invention. This is probably becausethe first binder-sealant layer (separating the substrate and thecolorant layer of the sandwich indicia) provides further protectionagainst fluid movement into and out of the colorant layer.

While this invention has been described with reference to certainspecific embodiments, it will be recognized by those skilled in this artthat many variations are possible without deporting from the scope andspirit of the invention.

What is claimed is:
 1. A method for making an indicia-containing foodproduct comprising the steps of:a) providing a casing article having aplasticized flexible inner surface and a desired indicia comprising awater soluble dry colorant layer with its bottom surface innondiffusible association with said casing inner surface and a waterinsoluble binder-sealant superimposed over and entirely enclosing thecolorant top surface in adhering relationship, the binder-sealantperimeter outwardly extending beyond the colorant layer extremities soas to directly contact the surrounding casing inner surface in adheringrelationship; b) filling said casing with water moisturized processablefood such that the water moisturized food outer surface is in directcontact with said binder-sealant on the casing inner surface; c)processing the food-containing casing at elevated temperature to cooksaid food and simultaneously substantially completely transfer thebinder-sealant covered colorant indicia from said casing inner surfaceto the water moisturized processed food outer surface; and d) peelingthe casing from the indicia-containing processed food outer surface. 2.A method according to claim 1 wherein said casing is cellulosic.
 3. Amethod according to claim 1 wherein said casing is a thermoplastic film.4. A method for making an indicia-containing food product comprising thesteps of:a) providing a cellulosic casing article having a plasticizedflexible inner surface and a desired indicia comprising a water solubledry colorant layer with its bottom surface in contiguous andnondiffusible association with said cellulosic casing inner surface anda water insoluble binder-sealant superimposed over and entirelyenclosing the colorant top surface in adhering relationship, thebinder-sealant perimeter outwardly extending beyond the colorant layerextremities so as to directly contact the surrounding casing innersurface in adhering relationship; b) filling said casing with watermoisturized processable food such that the water moisturized food outersurface is in direct contact with said binder-sealant on the casinginner surface; c) processing the food-containing casing at elevatedtemperature to cook said food and simultaneously substantiallycompletely transfer the binder-sealant covered colorant indicia fromsaid casing inner surface to the water moisturized processed food outersurface; and d) peeling the casing from the indicia-containing processedfood outer surface.
 5. A method according to claim 4 including the stepsof adhering said indicia to the casing article outer surface andthereafter inverting said casing article to position said indicia onsaid inner surface as said substrate.
 6. A method according to claim 2wherein said processed food is meat.
 7. A method according to claim 2wherein said processed food is poultry.
 8. A method according to claim 3wherein said processed food is carbohydrate.
 9. A method according toclaim 4 wherein said processed food is cheese.
 10. A method according toclaim 5 wherein said colorant is caramel.
 11. A method according toclaim 10 wherein said binder-sealant is shellac.
 12. A method accordingto claim 10 wherein said binder-sealant is zein.
 13. A method for makingan indicia-containing food product comprising the steps of:a) providinga thermoplastic film casing article having a flexible inner surface anda desired indicia comprising a water soluble dry colorant layer with itsbottom surface in contiguous and nondiffusible association with saidthermoplastic film casing inner surface and a water insolublebinder-sealant superimposed over and entirely enclosing the colorant topsurface in adhering relationship, the binder-sealant perimeter outwardlyextending beyond the colorant layer extremities so as to directlycontact the surrounding casing inner surface in adhering relationship;b) filling said film casing with water moisturized processable food suchthat the water moisturized food outer surface is in direct contact withsaid binder-sealant on the casing inner surface; c) processing thefood-containing film casing at elevated temperature to cook said foodand simultaneously substantially completely transfer the binder-sealantcovered colorant indicia from said casing inner surface to the watermoisturized processed food outer surface; and d) peeling the film casingfrom the indicia-containing processed food outer surface.
 14. A methodfor making an indicia-containing food product comprising the steps of:a)providing a casing article having a plasticized flexible inner surfacewith an indicia comprising a first binder-sealant layer having itsbottom surface adhered to the casing inner surface in nondiffusibleassociation therewith, a water soluble dry colorant layer with its undersurface superimposed on the top surface of said first binder-sealantlayer in adhering and nondiffusible relationship therewith, and a secondbinder-sealant layer superimposed over the colorant upper surface andextending beyond the colorant layer extremities in adhering relationshipso as to entirely enclose said colorant layer, with at least one of saidfirst and second binder-sealant perimeters outwardly extending beyondthe colorant extremities so as to directly contact the surroundingcasing inner surface in adhering relationship, said first and secondbinder-sealants having melting points above about 100° F. and beingwater insoluble; b) filling said casing with water moisturizedprocessable food such that the water moisturized food outer surface isin direct contact with said second binder-sealant layer; c) processingthe food-containing casing at elevated temperature to cook said food andsimultaneously substantially completely transfer the firstbinder-sealant, colorant, second binder-sealant sandwich indicia fromsaid casing inner surface to the water moisturized processed food outersurface; and d) peeling the casing from the indicia-containing processedfood outer surface.
 15. A method according to claim 14 wherein saidcasing is cellulosic.
 16. A method according to claim 14 wherein saidcasing is a thermoplastic film.
 17. A method for making anindicia-containing food product comprising the steps of:a) providing acellulosic casing article having a plasticized flexible inner surfacewith an indicia comprising a first binder-sealant layer having itsbottom surface adhered to the cellulosic casing inner surface innondiffusible association therewith, a water soluble dry colorant layerwith its under surface superimposed on the top surface of said firstbinder-sealant layer in adhering and nondiffusible relationshiptherewith, and a second binder-sealant layer superimposed over thecolorant upper surface and extending beyond the colorant layerextremities in adhering relationship so as to entirely enclose saidcolorant layer, with at least one of said first and secondbinder-sealant perimeters outwardly extending beyond the colorantextremities so as to directly contact the surrounding casing innersurface in adhering relationship, said first and second binder-sealantshaving melting points above about 100° F. and being water insoluble; b)filling said casing with water moisturized processable food such thatthe water moisturized food outer surface is in direct contact with saidsecond binder-sealant; c) processing the food-containing casing atelevated temperature to cook said food and simultaneously substantiallycompletely transfer the first binder-sealant, colorant, secondbinder-sealant sandwich indicia from said casing inner surface to thewater moisturized processed food outer surface; and d) peeling thecasing from the indicia-containing processed food outer surface
 18. Amethod according to claim 17 including the steps of bonding said indiciato the casing article outer surface and thereafter inverting said casingarticle to position said indicia on said inner surface as saidsubstrate.
 19. A method according to claim 17 wherein said processedfood is meat.
 20. A method according to claim 17 wherein said processedfood is poultry.
 21. A method according to claim 17 wherein saidprocessed food is carbohydrate.
 22. A method according to claim 17wherein said processed food is cheese.
 23. A method according to claim17 wherein said colorant is caramel.
 24. A method according to claim 17wherein at least one of said first and second binder-sealants is zein.25. A method according to claim 17 wherein at least one of saidbinder-sealants is shellac.
 26. A method according to claim 17 whereinsaid indicia is spaced grill-marks.
 27. A method according to claim 17wherein said indicia is a logo.